Nutrient uptake of a mixed oak/beech forest in Flanders (Belgium)

Abstract

A 72-year-old mixed oak/beech stand has been studied on the element (N, P, K, Ca and Mg) content in its woody biomass, in the wood increment and in the litter fall. Crown leaching and nutrient uptake have been calculated respectively according to Ulrich (1983) and to Cole & Rapp (1981). Eight oaks and six beeches have been sampled, regression equations between the tree element content and the stem volume have been calculated in order to scale up from the tree to the stand level.The annual amount of elements taken up is 70 kg N, 4,9 kg P, 69,3 kg K, 43 kg Ca and 6,1 kg Mg per ha. For K, Ca and Mg a large part of the nutrient uptake is due to crown leaching. The amount of Nand P in the litter fall constituted the largest part of the uptake of Nand P. For the elements K, Ca and Mg, crown leaching is very important in the nutrient cycling: crown leaching amounts respectively 63%, 21% and 43% of the annual return of these elements from the canopy to the forest floor.

Comparison of biomass and nutrient content between oak (Quercus petraea) and hornbeam (Carpinus betulus) trees in a coppice-with-standards stand in Chimay (Belgium)

“…In agreement with our results, decreasing N, P, K, Mg, S concentrations from thinner live branches to thicker ones were also reported by Duvigneaud et al [10] for oak and hornbeam, and by Mussche et al [20] for oak only. The contrasting evolution of Ca concentrations between wood and bark tissues as a function of oak branch diameter was also observed by Duvigneaud et al [10].…”

“…Very high concentrations of Ca in oak stem bark were also mentioned by Mussche et al [20] and De Visser [8]; our values are however about twice higher and reach those measured by Duvigneaud et al [10] for a mixed oak, beech and hornbeam -broadleaved forest growing on a calcareous soil in Virelles (Belgium). High Ca bark concentrations, also reported for other species by various authors, would result from immobilisation of this nutrient during cell wall lignification [1,6].…”

“…IV and Fig. 1) were already noticed for both species in several studies [8,10,20]. Differences in nutrient concentrations between oaks and hornbeams were found for all nutrients except K in this study; such species related differences were also reported by Duvigneaud et al [10] and suggest a possible discriminant effect of species on the chemical composition of tree components [19].…”

“…According to Bamber and Fukazawa [3], this transition may be interpreted as a nutrient resorption from senescing sapwood rings to cells of younger ones. Mussche et al [20], however, observed decreasing P concentrations from heartwood to sapwood. Nutrient concentrations previously reported for heartwood and sapwood are generally close to ours except values from Lévy et al [17] which are systematically higher; according to these researchers, heartwood concentration would reflect soil chemical properties evolution while sapwood concentrations would rather result from nutrient translocations occurring between rings.…”

“…stand located in the French Ardennes [21,25], the four other ones are located in Belgium ( [9,11,13,20], this study). Numbers between brackets are ratios of stand nutrient contents to stand biomass (i.e.…”